Asclepias tuberosa L.
Butterfly Milkweed, Butterflyweed, Orange Milkweed, Pleurisy Root
Butterfly milkweed is so named because it attracts butterflies—queen (Danaus plexippus) and monarch butterflies (Danaus gilippus). They lay eggs on the leaves, as a food source for the larvae when they hatch. In my opinion, though, butterfly milkweed should have been named for its color. Orange is a relatively rare flower color, and this orange is striking, practically fluorescent in its intensity. Between the flowers and the butterflies they attract, these plants are popular with gardeners.
Identification: Plants are 12-39" (30-100 cm) tall, with hairy stems and spirally arranged leaves. Leaves are lance-shaped (lanceolate), 1¾-4½" (5-12 cm) × ¾-1" (2-3 cm). Most milkweed stems and flowers produce a milky latex when cut, but the sap of this species is clear. Flowers are brilliant orange or yellow-orange, shaped very much like those of other milkweeds, in dense clusters 2-5" (5-12 cm) in size atop the stem. Each flower is about ⅜" (9.5 mm) in size, with with a five-pointed star and five petals that are bent back (reflexed). Flowers appear from May to September. Seed pods are spindle-shaped, covered with fine hairs, and 4-5" (10-12 cm) long. They open to reveal many seeds, each equipped with its own silken parachute.
Edibility: Poisonous Roots and all parts of this plant contain resinoids, alkaloids and cardiac glycosides that, in quantity, can cause vomiting, stupor, weakness, and spasms. (The name pleurisy root derives from its historical use by some North American Indians in treating pain and inflammation of pleurisy. It was also sometimes used as an expectorant, or for the treatment of other lung ailments.)
Asclepias tuberosa at Illinois Wildflowers
Asclepias tuberosa on Missouriplants.com
Asclepias tuberosa at Southeastern Arizona Wildflowers and the Plants of the Sonoran Desert
Asclepias tuberosa on the USDA Plants Database
Asclepias tuberosa on Wikipedia
Asclepias tuberosa at the Lady Bird Johnson Wildflower Center
Asclepias tuberosa at the Missouri Botanical Garden
Asclepias tuberosa on Erv Evans' site at the North Carolina State University College of Agriculture and Life Sciences
Asclepias tuberosa on Plants for a Future, a resource and information centre for edible and otherwise useful plants
Asclepias tuberosa at the University of Wisconsin's Robert W. Freckmann Herbarium
Asclepias tuberosa at Minnesota Wildflowers
Asclepias tuberosa description by Thomas H. Kent, last updated 5 Oct 2016.
Range: Zones 3-9: